Internal-combustion engine and method of operating the same



`Fam. 6, 93l. w. M. zAlKowsKY INTERNAL COMBUSTION ENGINE AND METHOD OFOPERATING THE-SAME 2 Sheets-Sheet l Filed Feb. 16, 1929 MM, mf

jan- 5, 1931 y w. M. zAlKoWsKY 1,788,077

INTERNAL COMBUSTION ENGINE AND METHOD OF OPERATING THE SAME Filed Feb.16, 1929 2 Sheets-Sheet, 2

Patented Jan. 6, 1931 UNITED STATES PATENT- oFFlcE WLADIMIR M.ZAIKOWSKY, OF PASADENA, CALIFORNIA, ASSIGNOR TO STANDARD OIL DEVELOPMENTCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWAREINTERNAL-COMBUSTION ENGINE AND METHOD OF OPERATING THEySAME Applicationled February 16, 1929. Serial No. 340,439.

. This invention relates to improvements in internal combustion engines,and method of operating the same.

One of the features of the invention is the utilization and cooling o fa portion of the exhaust gases for scavenging the cylinder.

Another feature of the invention is the utilization of a portion of thecooled exhaust gases for the scavenging of the cylinder near the end ofthe exhaust stroke of the piston in order to increase the weight of theresidual exhaust remaining in the clearance by lowering its temperature.

Other features and advantages of my invention will appear more fully asI proceed with my specification.

In the accompanying drawings, I have shown, as an example, afour-cylinder` engine, but it is understood that the engine may havefewer or more cylinders, as desired.

In the accompanying drawings, Figure l is a vertical sectional viewtaken as indicated by the line 1, 1, of Fig. 2; Fig. 2 isa. broken planview; and Fig. 3 is a vertical sectional view ofthe cooling chamber, asindicated by the line 3, 3, of Fig. 2.

I need describe but one cylinder. As shown in the drawings, 10 indicatesthe usual crank case; 11, the block; and 12, the cylinder. Numeral 13indicates the piston; 14V the connecting rod; and 15, the usual crankshaft.

The usual inlet and exhaust valves are indicated by 17 and 16,respectively, and these may be operated in any convenient manner, as bymeans of the valve rods 18 and cam shaft 18, driven at half enginespeed.

This much of the engine may be of any well known construction in a fourcycle engine, the type illustrated being that com" monly found inautomobile engines.

To this well known construction I have added two additional valves 24and 25 which are opened by means of cams on the cam shaft 19, butnormally held closed by means of springs 26. The cams 19 on the camshaft 19 operate through push rods 19al operating the rocker arms 19bwhich depress the valve stems 24 and 25', respectively.

The value 24 connects with a passage 33 which, in turn, connects to amanifold 32 leading to the pipe coil R in a cooling chamber 100. Gases,after being cooled in the pipe coil R, leave the same through the pipe31 which is connected to the manifold 2-8 leading to the passage 27controlled by the valve 25. The pipe coil R in the cooling chamber 100may be cooled by water surrounding the same. For example, water may beintroduced at 101 and permitted to escape at 102. For example, water maybe introduced into the opening 101 by the regular water pump (not shown)of a motor vehicle, such pump obtaining the water from the radiator.After leaving the cooling chamber through the opening 102, the water maybe introduced into the water spaces of the cylinder block and head inthe usual manner for cooling the same. The direction of flow of gasesinto and out of the cooling chamber is indicated by the arrows in Fig.3. The pipe 32 receives the hot gases from the cylinders and the pipe 31delivers them back in cooled condition to the cylinders. Forconvenience, the valve 24 which receives the hot gases from the cylindermay be referred to as the hot valve and the valve 25 which returns thecooled gases to the cylinder may be referred to as the cold valve.

The cycleof operation of this-engine is that of the ordinar Otto cycle,except that this cycle is modi ed by the action of the additional valves24 and 25. In general, it

may be stated that the hot valve 24 is opened late in the explosionstroke and the cold valve 25 is opened near the end of the exhauststroke, to scavenge the hot exhaust gases remaining in the clearancespace with cooled exhaust gases.

The exact timing of the additional valves will Vary with differentusages and practices and may be made as desired. In general. it seemsthat it may be advisable to open the hot valve 24 at the end of theexplosion or expansion stroke just before the regular exhaust valvebegins to o pen.` Hot gas will, therefore. flow from the cylinder intothe cooling chamber. As soon as the regular exhaust valve opens, thepressure in the cylinder will drop rapidly; but the valve should be sotimed that before the pressure in the cylinder drops below the pressurethat is desired in the cooling chamber, the valve 24 should cylinder ofhot exhaust close, thus preventing back ow of gases from the coolingchamber through the valve 24. For example, it appears that the hot valvemay commence to open about 80 before lower dead center and completelyclose about 40 before lower dead center on the expansion stroke. Theopening of the valve may be later than this if less pressure is desiredin the cooling chamber.

The cold valve should open at theffend of the exhaust stroke in order toscavenge the clearance space of the hot exhaust gases. The exact timingof this valve to produce the best results will vary with different usaes. It appears, for example, that the col valve 25 may commence to openabout 75 before top dead center and-completely close about 15 before topdead center on the exhaust stroke. il

The elimination of some of the hot exhaust gases, and replacing the samewith' cooled exhaust gases, serves to lessen the detonation in theoperation of the engine.

Each cylinder, in'turn, communicates with the cooling coil R during thelatter part of its worln'ng stroke to deliver hot burned gases to thecooling coil and receives from the cooling coil a cooled flow of burnedgases at the end of the exhaust stroke to scavenge the gases.

It will be seen that the cold valve 25 is in the head of the motor sothat the cooled gases entering the cylinder during the supercharging aredirected more or less against the piston, thus servingto cool it. Thehot valve (24 is also in the head, thus facilitati flow "of hot exhaustases from the cylin er to the cooling coil The cold valve 25 is also soarranged that the supercharging or dilut ing cooled exhaust gas entersthe cylinder at a point removed from the spark plug 45, thus interferingless with ignition. It is to be noted, also, that the cold valve 25 issubstantially diametrically opposite the regular exhaust valve 16, thusincreasing the efficiency of the scavenging. Y

While I have shown and described certain embodiments of my invention, itis to be understood that it is capable of many modiications. Changes,therefore, in the construction and arrangement may be made with- A outdeparting from the spirit and scope of the invention as disclosed in theappended claims, in which it is my intention to claim all noveltyinherent in my invention as broadly as possible, in viewof the priorart.` f

It 'is to be noted that when the cooled exhaust replaces the hot exhaustgas the temperature of the charge is lowered, and the proportion of theexhaust inthe charge is increased without substantial reduction in thevolumetric eiiciency of the engine.

What I regard as new, and desire to secuie by Letters Patent, is: 1. Aninternal combustion engine having a cylinder, a piston slidable therein,inlet and exhaust valves, a cooling chamber, auxiliary means for openingcommunication between said cylinder and chamber during the latter partof the expansion stroke to force burned gases into the chamber, andmeans for` opening communication between said cylinder and chamberduring the latter part ofthe exhaust vstroke topermit cooled exhaustgases to re-enter the cylinder.

2. An 'internal combustion engine as claimed in claim 1, in Which thecooling chamber is tubular, the exhaust gases leaving the cylinderentering one end of said tubular chamber and returning to the cylinderfrom the other end of said tubular chamber.

3. Anf internal combustion engine as claimed in claim 1, in which thecommunications between the cylinder and the cooling chamber arecontrolled by valves.

4. The method of operating an internal combustion engine, consisting oftrapping a portion of the exhaust gases, cooling the same, andre-introducing such cooled exhaust gases into the cylinder toward theend of the exhaust stroke.

5. The method of operating an internal* combustion engine, consisting oftrapping a portion of the exhaust gases during the expansion stroke,cooling the same, and reintroducing such exhaust gases into the cylinderduring the exhaust stroke.

6. An internal combustion engine having a cylinder with anopening oropenings in the head, a cooling chamber in communication with saidopening or openings, and means controlling said opening or openingswhereby hot exhaust gases are introduced into the cooling chamber nearthe end of the explosion stroke and re-introduced into the cylinder nearthe end of the exhaust stroke.

An internal combustion engine having a cylinder with two openings in thehead thereof; a tubular cooling chamber, with its ends in communicationwith said openings; valves controlling said communications; and meansfor opening one of said valves during the explosion stroke and the otherof said valves during the exhaust stroke.

In witness whereof, I have hereunto set my hand this 6th day ofFebruary, 1929.

WLADIMIR M. ZAIKOWSKY.

